title: Convergence in feeding posture occurs through different genetic loci in independently evolved cave populations of Astyanax mexicanus.
abstract: When an organism colonizes a new environment, it needs to adapt both morphologically and behaviorally to survive and thrive. Although recent progress has been made in understanding the genetic architecture underlying morphological evolution, behavioral evolution is poorly understood. Here, we use the Mexican cavefish, Astyanax mexicanus, to study the genetic basis for convergent evolution of feeding posture. When river-dwelling surface fish became entrapped in the caves, they were confronted with dramatic changes in the availability and type of food source and in their ability to perceive it. In this setting, multiple independent populations of cavefish exhibit an altered feeding posture compared with their ancestral surface forms. We determined that this behavioral change in feeding posture is not due to changes in cranial facial morphology, body depth, or to take advantage of the expansion in the number of taste buds. Quantitative genetic analysis demonstrates that two different cave populations have evolved similar feeding postures through a small number of genetic changes, some of which appear to be distinct. This work indicates that independently evolved populations of cavefish can evolve the same behavioral traits to adapt to similar environmental challenges by modifying different sets of genes.
authors.affiliation: Department of Genetics, Harvard Medical School, Boston, MA 02115.
authors.forename: Johanna E
authors.initials: JE
authors.lastname: Kowalko
authors.forename: Nicolas
authors.initials: N
authors.lastname: Rohner
authors.forename: Tess A
authors.initials: TA
authors.lastname: Linden
authors.forename: Santiago B
authors.initials: SB
authors.lastname: Rompani
authors.forename: Wesley C
authors.initials: WC
authors.lastname: Warren
authors.forename: Richard
authors.initials: R
authors.lastname: Borowsky
authors.forename: Clifford J
authors.initials: CJ
authors.lastname: Tabin
authors.forename: William R
authors.initials: WR
authors.lastname: Jeffery
authors.forename: Masato
authors.initials: M
authors.lastname: Yoshizawa
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D059552:Caves; D060126:Characidae / Q000502:physiology*; D019143:Evolution, Molecular; D005247:Feeding Behavior / Q000502:physiology*; D056426:Genetic Loci / Q000502:physiology*